Welcome to the forum and thanks for your service! Campbell has some very nice deer on it for sure. As far as TWRA land, almost every bit of public land gets pressured--some more than others. As far as 3D goes..... you are in a 3D hotspot being in Mid-TN! At the top of the forum there is a calender for 3D shoots in the area made by DixieCrafter. Almost every weekend, except for ASA weekends, there is a shoot to be found somewhere in Mid-TN. You have Old Hickory Lake Bowmen Club, Montgomery County Bowhunters, Cheatham Archery Club, Frog's Timberland Archery, LazyDay in Paris and a lot of others.
As far as public ranges go, Old Hickory Lake Bowmen Club in Hermitage is about the only one that is open year around, 7 days a week. We do not keep 3D targets up, but we do have target buttresses all over the property that you can walk through and practice on from 10yds to 70+ yards.